Difference Between Polyurethane and Polycarbonate

The key difference between polyurethane and polycarbonate is that polyurethane has urethane linkages whereas polycarbonate has carbonate groups.

Both polyurethane and polycarbonates are polymer compounds having a complex structure containing a large number monomers. Most of the times, we name the polymer material depending on the type of monomer(s) used in the production. However, polyurethane and polycarbonates are named as such since polyurethane has urethane linkages and polycarbonate has carbonate groups.

CONTENTS

1. Overview and Key Difference
2. What is Polyurethane
3. What is Polycarbonate
4. Side by Side Comparison – Polyurethane vs Polycarbonate in Tabular Form
5. Summary

What is Polyurethane?

Polyurethane is a polymer made from isocyanates and polyols. The polymer is different from most other polymer materials because other polymer materials are named depending on the monomers, but this polymer is named because of the urethane linkages repeating throughout the material.

When considering the production of the material, it uses an exothermic reaction between alcohols with two or more functional groups (we call them “polyols”) and isocyanates having more than one isocyanate-reactive group. These two compounds are the monomers for polyurethane. This means, there are no urethane monomers in this material.

There are many important uses of polyurethane. Mostly it is useful to make flexible foam for mattresses, cushions, etc. Secondly, it is useful for rigid foam production. Furthermore, there are some other uses such as moulded foam formation, elastomer production, for adhesives, sealers, coatings, etc.

What is Polycarbonate?

Polycarbonate is a polymer made from bisphenol A and phosgene. This is a durable material. However, it has a high impact resistance and low scratch resistance. Moreover, it can withstand high temperatures. It is also transparent to visible light, which makes it important in the production of glassware such as lenses.

In the production process, the first step involves the treatment of bisphenol A with NaOH for the deprotonation of hydroxyl groups of the bisphenol A molecule. Then, the resulting compound can react with phosgene to form polycarbonate polymer material.

What is the Difference Between Polyurethane and Polycarbonate?

Polyurethane is a polymer made from isocyanates and polyols while polycarbonate is a polymer made from bisphenol A and phosgene. The key difference between polyurethane and polycarbonate is that polyurethane has urethane linkages whereas polycarbonate has carbonate groups.

Furthermore, there are many important properties of both these materials; polyurethane is important because of its flexibility, low density, durability, etc. and polycarbonate is important because of high impact resistance, low scratch resistance, transparent, can withstand high temperatures, etc. Therefore, this is another major difference between polyurethane and polycarbonate.

The following infographic presents the difference between polyurethane and polycarbonate in more detail.

Summary – Polyurethane vs Polycarbonate

Polyurethane and polycarbonate are complex polymer materials. These compounds have different properties that are very important in different applications. The key difference between polyurethane and polycarbonate is that polyurethane has urethane linkages whereas polycarbonate has carbonate groups.

Reference:

1. Lazonby, John. “Polyurethanes.” The Essential Chemical Industry Online, Available here.
2. “Polycarbonate.” Wikipedia, Wikimedia Foundation, 2 May 2019, Available here.

Image Courtesy:

1. “Polycarbonate water bottle” By Donmike10 (talk) – by Donmike10 (talk) (Public Domain) via Commons Wikimedia
2. “Goturethane Samples” By Goturethane – (CC BY-SA 4.0) via Commons Wikimedia